Mobile forage freezer



4 Sheets-Sheet 1 FIG. I

E. D. RAZUM MOBILE FORAGE FREEZER April 2s, 1966 Original Filed Aug. l, 1963 FIGB me/wko@ Ernest D. Razum Samui l Fill!!! E April 26, 1966 Original Filed Aug. l. 1963 E. D. RAZUM MOBILE FORAGE FREEZER 4 Sheecs--Sheeil 2 April 26, 1966 E. D. RAzuM 3,247,893

MOBILE FORAGE FREEZER Original Filed Aug. l, 1963 4 Sheets-Sheet 3 5 gmc/nm Ernest D. Razum April 26, 1966 E. D. RAzuM MOBILE FORAGE FREEZER 4 Sheets-Sheet 4 Original Filed Aug. 1, 1963 FIG .6

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Ernest D. Razum 3241,@93 Patented Apr. 26, 1966 2 claims. (ci. 16s-ss) This application is a division of application Serial No. 299,279, filed August 1, 1963.

This invention relates to a novel machine for -preservingall type of forage. More particularly, the invention relates to a novel evaporator element included within said machine.

According to the invention of U.S. patent application Serial No. 299,279, forage is frozen immediately after having been cut by mobile units, thus enabling the farmer to immediately realize a simultaneous gathering and preserving of forage. Under past and present practices in this art, it is necessary to perform a series of distinct steps, often carried out at various locations, to achieve a final end product, i.e., a stored quantity of forage ready for use whenever desired. Further, the practice of prior and present methods and procedures in this art entails the loss of substantial nutritive values in the final forage product. Such a loss in nutrients sometimes approaches 25% or more.

In the food arts, it has been recognized for some time that low temperature refrigeration applied very rapidly to crops after they are harvested, will preserve nearly 100% of the nutrient content of the product. Up to the present time, however, this realization has not found application in preserving food, particularly for animal consumption.

The mobile forage freezing machine is in combination with known forageV harvesting machines and forage as it is harvested is immediately frozen involving a freezing process wherein a portion of the freezing is accomplished through evaporative cooling and another portion is accomplished through a mechanical refrigeration system. The present invention is concerned with a novel evaporator element forming a part of the mechanical refrigeration system.

It is accordingly an object of the present invention to provide a novel evaporator element for use in a mechanical' refrigeration system.

It is another object of this invention to provide a novel evaporator element in a mechanical refrigeration system whereby a liquid refrigerant may be volatilized and returned to the refrigeration cycle while at the same time retaining liquid refrigerant.

It is another object of this invention to provide a novel evaporator element in the form of a hollow disc comprising oppositely disposed wall members bounded by an outer peripheral wall member and a hub member. A collar member is disposed coextensive with the hub member on the outer surface of one of the walls. A first fluid passagewayis provided for introducing liquid refrigerant into the disc which extends through said collar member and one of the walls to the interior of the disc. A second fluid passageway is provided which extends through the opposite wall and opposite the first fluid passageway for permitting refrigerant to flow from one disc to another. A third fluid passageway is provided which extends continuously through the collar member and the walls for the ilow 'of gaseous refrigerant. A fourth fluid passageway is provided within said walls which is disposed vertically to a point intermediate the peripheral member and communicates with the third fluid passageway and the interior Of the disc to permit withdrawal of gaseuos refrigerant from the interior of the disc.

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These and other objects of the present invention will become apparent from the following description.

In the drawings:

FIGURE l is a top View of the mobile forage freezer, according to this invention, shown in combination with a conventional forage harvester and a portion of a tractor.

FIGURE 2 is a side view of FIG. 1.

FIGURE 3 is a cross section taken along line 3 3 of FIG. 2.

FIGURE 4a is a cross section taken along line ia-4a of FIG. 3.

FIGURE 4b is a cross section taken along line dii-4b of FIG. 3.

FIGURE 5 is a partially cut-away view of an evaporator disc shown in FIG. 4b.

FIGURE 6 is a cross section of the evaporator disc of FIG. 5.

FIGURE 7 is a stretched out view of the annular heat exchanger chamber of FIG. 3.

FIGURE S is an end view, partially schematic, of the feed roller driving mechanism and deflection blade actuated by a solenoid.

FIGURE 9 is Ia schematic view of the refrigeration circuit of the mobile freezing unit of this invention.

Referring now to FIGURES 1 and 2 of the drawings, the numeral 8 denotes a portion of a tractor or other pulling implement for driving the freezer of this invention along the ground. Within the scope of the invention, the freezer may carry its own motive power. The numeral 10 denotes a conventional forage harvester, representing any one of a number of types presently available on the market and includes an upper discharge portion 11. The function of the harvester 1@ is to cut and chop the standing crop and supply the chopped forage product into the front portion of the mobile forage freezer of this invention. The chopped product, as it enters into the freezer, is made up, by way of example, of approximately moisture and 15% dry matter.

Referring now to FIGURE 3 of the drawings, numeral 12 denotes a heat-exchanger fan, adapted to rotate in the indicated direction, and operated by a suitable auxiliary engine indicated by the numeral 13 of FIGURE l. The function of fan 12 is to below the chopped forage product, delivered by harvester 10, through van annular heat eX- change chamber denoted by the numeral 14 (see FIG- URE 3). The chopped forage product is blown through the annular heat exchange chamber 141 and comes in contact during its journey with fins 15 in the chamber, thereby utilizing the moisture content of the product to withdraw heat from the fins 15 and the refrigerant which is circulated in the interior of the heat exchange chamber. This is a direct product evaporation system.

The numeral 16 of FIGURE 3 denotes a filter which may be formed of burlap and upon which excess moisture may accumulate and thereafter drop out of the device. This moisture isthat which comes through the forage product as it bounces against the walls of'chamber 14, the tins 15 and especially as the product passes through the feed rollers i6 and 47. A great amount of moisture is also eliminated through the open top of the hopper 24. This moisture is in the form of evaporated water which is carried out in the air that is blown around the annular chamber 14. Thisv moisture and air carries the largest part of the heat out of the machine. The numeral 17 denotes the interior of the annular heat exchanger (condenser) and positioned therein is a plurality of vanes 18. The numerals 19 and 20 denote refrigerant inlet portions feeding into the interior 17. The arrangement of the vanes 18 is such that the flow of the refrigerant entering the interior follows a zig-zag path or pattern and directs the refrigerant to the front of the machine and then to the back of the machine and then to the front of the machine and then to the back of the machine, etc. This back and forth iiow of the refrigerant is due to the fact that the first sectional vane or wall 13 extends the entire length of the machine and has an opening in the back and the next adjacent vane which is parallel thereto does not have an opening in the back, rather it has an opening in the front. This tortuous iiow path provides a large condenser surface area.

The numeral 21 denotes an exit port or passageway for the refrigerant from the condenser 1'7' to a receiver 22. The receiver 22 will be more fully described later in connection with a detailed description of the refrigeration circuit.

The numeral 23 denotes a rotary agitator in the bottom of an elongated trough 24 and functions to preclude clogging in the trough. The numeral 25 denotes an exit at the rear portion of the path of the forage leading into the hopper 24. The numerals 26 and 27 denote two circular distribution chains, each of which are connected by a plurality of generally parallel angle elements 28. As seen from an inspection of FIGURE l, the chains 26 and 27, driven through a motor M, cause translation of the lower angle members 28 towards the front of the machine and attendant directing of the forage product which falls into trough 24 from exit 25 to the front of the forage freezer. Both the agitator 23 and the fan 12 extend the length of the hopper 24, as does the exit 25 of chamber 14.

The numeral 29 (FIGURE 3) denotes a cylindrical body of insulation suitably covered. Another generally cylindrical element, denoted by the numeral 3u (FIG. 4b) is situated within the cylinder 29 and is adapted to rotate about a central axis. The numeral 31 (FIG. 4b) denotes a suitable gear driving connection between the cylindrical member 30 and a drive shaft 32. The numeral 33 (FIG. 3) denotes one of a plurality of identical steel iingers integral with cylinder 3) and revolvable therewith. The numeral 34 denotes the spaces between successive steel fingers 33. It will be observed that each steel finger 33 has an apex 35 at the radially outermost portion thereof.

The numerals 36 and 37 (see FIGURES 4a and 4b) denote the two end evaporator discs generically designated by the numeral 38. Each disc 33 is in the form of a flat, hollow closed cylinder and carries a collar or hub 39 (FIGS. 5 and 6) preferably integral therewith and projecting from one side or face thereof. Perhaps best shown in FIGURES and 6 of the drawings, each evaporator disc 38 includes a central passageway 40 extending completely through the collar 39. Numeral 41 denotes a thickened portion of limited annular extent extending completely between the opposite faces of the cylinder and provided therein with a radial passageway 42. The numeral 43 denotes a truncated surface on each hub 39 adapted to receive a cutting member 44 (see FIGURE 3). From an inspection of FIGURES 4a and 4b, together with FIGURE 3, it will be seen that the steel fingers 33, together with the spaces 34 defined therebetween, rotate relative to the insulating cylinder 29 and the plurality of aligned evaporator discs 38.

The numeral 45 (FIGURE 3) denotes generally a feeding combination of elements and includes a pair of oppositely rotating rolls 46 and 47, each including a plurality of spaced hubs, adjacent a curved covering plate 48 having a displaced portion 49 below which is pivotally mounted an adjustable feeding detiector blade 50. The blade 50 includes an outer bent-back portion 51 to preclude the entry of chopped forage behind the detlector blade. It will be observed that the deector blade 5t) runs the entire length of the freezer and, from an inspection of FIGURE 4b, the protruding portion of the oppositely rotating members 46 and 47 are positioned opposite the spaces between the evaporator discs 38.

Before proceeding further with description of the invention, a description of the operation of the above enumerated elements will now be set forth.

The tractor 8 is run across the harvesting field and the forage harvester 10 cuts the forage and blows it through spout 11 into the front end of the freezer. The forage, encountering the action of rotating fan blade 12 (FIG. 3) is directed into the mouth of the heat exchanger chamber 14. The curvature of the fins 15 (FIG. 7) and their position relative to the air flow through the chamber 14 (FIG. 3) is such that a small amount of water is retained in the central part of each 1in 15 at all times during normal operation of the machine. This water is removed from the forage product. A portion of the product on each tin is in physical contact with the water retained on that n. The remaining product on each fin, not in contact with the water, is exposed to the air flow. As that portionof the product exposed to the air flow begins to dry out through evaporation, thus removing hea from the refrigerant in condenser 17, its specific Weight is reduced. At a predetermined or particular specific weight, the air flow is sufficient to dislodge this partly dried portion of the product from the fin and force it onward to either the hopper 24 or the rotating feed rollers 46 and 47. The forage product thus lost from each fin is replaced by new forage product coming from the hopper 24 (FIGURES 1 and 3) and having a specific weight high enough to keep it lodged on the tins. The formation of scale, from minerals in Water, on the interior surfaces of chamber 14 and upon fins 15 is precluded by the bombardment of forage particles thereagainst, thereby mitigating this problem common to many evaporative cooling systems.

The freezer uses several different methods to remove the heat from the refrigerant as the refrigerant passes through the refrigeration cycles. In the first method of heat transfer, heat from the refrigerant is conducted to the water lodged on the fins 15. The heat from the water on these fins is transferred to the water on the forage product by conduction. Evaporation by the air current on the exposed surface of the forage-product removes this heat. This air circulation through the annular chamber 14 now contains the pick-up heat and is discharged through the top opening of the hopper 24 through exit 25.

In the second method of heat transfer, heat from the refrigerant is conducted to the common wall between the condenser 17 containing the refrigerant and the annular chamber 14 containing the fins 15. The direct ow of outside cooler air removes some of the heat by direct evaporation of the moisture on these surfaces. (The moisture is deposited thereon by the moist product.)

In the third method of heat transfer in this refrigeration process, the moisture-contained-product and the outside air have a lower temperature than the air in the annular chamber 14 and much lower than the temperature of the walls forming the annular chamber and the fins 15 contained thereon. This cooler product and cooler outside air naturally lowers the temperature of the air in the chamber by their mere presence in the annular chamber. The bombardment of the cooler outside air and the cooler moisture-contained-product on the annular walls and ns absorbs the heat from the annular chamber walls and the ns. The bombarding particles absorb heat from the fins and the annular walls and as they continue their path around the annular chamber they lose picked-up heat by evaporating some of the moisture in the particles into the owing air.

The fourth method of removing heat takes place on the outside surface of the freezer. This outside surface carries fins 52 which are exposed to the cooler outside air. The heat from the refrigerant in condenser 17 passes by conduction to the outer wall of the freezer and the outside fins 52. The heat on the outside wall and the tins is transferred to the outside air by convection and radiation.

The fins are shown positioned as to constrain the forage product to follow a helical path along the annular chamber from front to back of the freezing unit. One purpose of such a design is to direct the air around and between the tins -15 for evaporation. When the forage product reaches the area P (FIG. 3) adjacent assembly 45, the deflector blade Sil causes a portion of the product to impinge against rotating feed rollers 46 and 47 and force the product into the spaces 34 between the steel fingers 33. In this connection, note in FIGURE 8 that a spring 53 in combination with slots 54 in which the ends of roll 46 are supported acts to slightly compress the forage product as it enters the chamber 34.

Upon passing downward through chambers 34, i.e., passing radially inwardly, the forage product contacts the walls o f evaporator discs 38, these discs containing a suitable refrigerant such as ammonia. Heat is abstracted from the forage product and when, at the lower or radially innermost portion of the chambers 34, it is sliced off by knives 44 mounted on the hubs of evaporator discs 38. The formation of frost (an undesirable concomitant in thefreezing of foodstuffs) on the surface of the evaporator discs 38 is precluded by the rubbing thereagainst of both the fingers 33 and the forage product. After being chopped off by the knives 44, the now frozen forage product in the form of elongated cubes passes into chamber 55 provided with an auger 56 driven suitably by a pulley wheel 57. The length of the frozen forage product is determined by the speed of rotation of cylinder 30. The auger forces the forage out through the rear portion (see FIGURE 4b) of the freezer and into any suitable storage bin or Wagon for later transfer into a permanent storage area.

Refer now to FIGURE 4b, of the drawings, the numeral 58 denotes a control thermostat adapted to be set to any desired temperature by means of a manual control denoted by numeral 59. In the event that the final temperature of the product exiting through the tube 55 is not as cold as the selected temperature on the manual control, none of the forage product passes into the freezing area at point P because the solenoid 60 is de-energized and the deflector blade 50 closes. With the deflector 'blade in a closed position the forage product passes into elongated hopper 24 through exit mouth 25 wherein the action of the lower angles `28 causes the forage product to flow towards the front portion of the machine and this maintains an equal distribution into the hopper along the entire machine and into the agitator 23. It then passes to the fan 12 and thence to the entrance to chamber 14 for recirculation. When the solenoid 60 is de-energized, the motor 61 (FIG. 4b) which revolves the freezing zones 34 is also cut off to maintain the position of `the coldest forage for rst cutting -by the blade when the machine resumes operation.

It will be observed that a rheostat 62 is utilized in conjunction With the motor 61 to vary the speed of rotation of the freezing drum and thereby vary the length of the frozen product as it is cut by blades 44.

Referring to FIGURES 9 and 4a and 4b of the drawings, a description of the refrigeration circuitof the invention will now be `set forth. The numeral 62 (FIG. 9) denotes a low temperature compressor whose gaseous output is fed through passages 19 and 20 (FIGS. 3 and 9) to the interior of the condenser 17. It exits through conduit 21, at the bottom of the freezer, as a liquid, into a receiver 22 and from there to an accumulator 63. The accumulator 63 is provided with a float valve which maintains a constant level of the refrigerant inthe evaporator discs, the 'float is established on the same height as the top of the desired refrigerant level in the evaporator discs. The refrigerant is `fed to the evaporator discs from accumulator 63 through intake passageway 64, passes through aligned passageways 64a (FIG. 5) in the discs and exits through conduit 65 back to the compressor 62. It will be observed that the refrigerant enters the condenser 17 as a gas, is then cooled by air and evaporation. The refrigerant upon entering the evaporator discs at 64 as a liquid fills nearly the entire volume .Within each evaporator disc 38. Because the liquid refrigerant in the evaporator discs 38 abstractsheat from the forage as the forage passes radially inwardly through spaces 34, the refrigerant is heated, turning into a gaseous form, the gas passing from passageways 42 to passagewayzs 4l) and then exiting through conduit 65. Passages ttl (FIG. 6) are aligned and form a continuous duct communicating with conduit 65. The evaporator discs 3S abut each other with a gasket therebetween (not illustrated).

Considering the described refrigeration cycle somewhat more in relationship to the flow of forage, as the chopped forage passes into chamber 14 and passes therearound., exiting either at area P or exit 25, evaporative cooling takes place. The air flowing over the vanes 15 evaporates the moisture formerly contained .in the forage product and thus cools condenser 17. In the case of liquid ammonia as the refrigerant employed, the boiling point ofl the refrigerant in the evaporator disc 33 is 28 F. at the atmospheric pressure therein. AS the forage enters through point P and passes radially inwardly through chambers 34, heat is abstracted therefrom and the liquid ammonia in the evaporator discs, absorbing this heat, boils and hence passes into the gaseous phase. The gas exits through ports 42 and into aligned passageways 4@ and out through conduit 65 to the compressor 62.- There it is compressed from atmospheric (14.7 p.s.i.) pressure to approximately 170 p.=s.i. This increase raises the boiling point of the ammonia to approximately 100 F. The pressurized gas refrigerant is now sent through conduits 19 and 2i) to the condenser 17. There, the evaporative cooling from the moist forage and moving air causes the ammonia gas to condense into a liquid. As a further factor in condensing the gas to a liquid., at an outside ternperature of F.a typical summer temperature, the gaseous refrigerant coming from compressor 62 transfers heat to the ambient ai-r through fins 52. The ammonia, now in liquid form in condenser 17, is now fed to the accumulator 63 from a receiver 22, as above described.

Thus, the forage freezer of this invention, While utilizing a known mechanical refrigeration cycle, utilizes the evaporative cooling effect. from the moisture in the product upon which the device works to effect condensation of the refrigerant. Further, this same evaporative cooling reduces the tempera-ture of the forage product, thereby reducing the cooling demand on the closed cycle refrigerant system.

What is claimed is:

1. An evaporator element for a mobile forage freezing machine, said element having generally the .for-m -of a hollow disc and defined vby `oppositely disposed wall members bounded by an outer peripheral member and a hub member, a collar member coextensive with said hub member disposed on the outer surface of one of said walls, a first fluid passageway extending through said collar member and `one of said walls to the interior of said disc, a second fluid passageway extending through the opposite wall and opposite said first passageway, a third uid passageway extending continuously through said collar member andsaid walls, and a fourth fluid passageway between said walls disposed substantially vertically to a point intermediate said peripheral member and communicating with said third passageway and the interior of said disc.

2. An evaporator element for a mobile forage freezing machine, said element having generally the form of a hollow disc and defined by two oppositely disposed substan- `tially circular walls bounded by an outer peripheral rim and a concentric hub portion, a collar coextensive with said hub portionl disposed on the outer surface of one of said circular walls, a member disposed substantially vertically between said walls extending radially from said hub portion to a point intermediate said rim, a liquid passageway extending through :said collar and one of said Walls to the interior of said disc and aligned with a second liquid passageway which extends through the opposite Wall, a first gaseous passageway extending continuously through said collar, said Walls and said radial member, and a second gaseous passagway extending through said radial member and communicating with said rst gaseous passageway and the interior of said disc.

References Cited by the Examiner UNITED STATES PATENTS Broadhurst 165-92 Wallis 165-92 Birdseye 62-381 X Birdseye 62-381 Rettig 165-92 X EDWARD I. MICHAEL, Primary Examiner. 

1. AN EVAPORATOR ELEMENT FOR A MOBILE FORAGE FREEZING MACHINE, SAID ELEMENT HAVING GENERALLY THE FORM OF A HOLLOW DISC AND DEFINED BY OPPOSITELY DISPOSED WALL MEMBERS BOUNDED BY AN OUTER PERIPHERAL MEMBER AND A HUB MEMBER, A COLLAR MEMBER COEXTENSIVE WITH SAID HUB MEMBER DISPOSED ON THE OUTER SURFACE OF ONE OF SAID WALLS, A FIRST FLUID PASSAGEWAY EXTENDING THROUGH SAID COLLAR MEMBER AND ONE OF SAID WALLS TO THE INTERIOR OF SAID DISC, A SECOND FLUID PASSAGEWAY EXTENDING THROUGH THE OPPOSITE WALL AND OPPOSIE SAID FIRST PASSAGEWAY, A THIRD FLUID PASSAGEWAY EXTENDING CONTINUOUSLY THROUGH SAID COLLAR MEMBER AND SAID WALLS, AND A FOURTH FLUID PASSAGEWAY BETWEEN SAID WALLS DISPOSED SUBSTANTIALLY VERTICALLY TO A POINT INTERMEDIATE SAID PERIPHERAL MEMBER AND COMMUNICATING WITH SAID THIRD PASSAGEWAY AND THE INTERIOR OF SAID DISC. 